The Strategy to Survive Primary Malaria Infection: An Experimental Study on Behavioural Changes in Parasitized Birds

Abstract

Avian malaria parasites (Haemosporida, Plasmodium) are of cosmopolitan distribution, and they have a significant impact on vertebrate host fitness. Experimental studies show that high parasitemia often develops during primary malaria infections. However, field studies only occasionally reveal high parasitemia in free-living birds sampled using the traditional methods of mist-netting or trapping, and light chronic infections predominate. The reason for this discrepancy between field observation and experimental data remains insufficiently understood. Since mist-netting is a passive capture method, two main parameters determine its success in sampling infected birds in wildlife, i. e. the presence of parasitized birds at a study site and their mobility. In other words, the trapping probability depends on the survival rate of birds and their locomotor activity during infection. Here we test (1) the mortality rate of wild birds infected with Plasmodium relictum (the lineage pSGS1), (2) the changes in their behaviour during presence of an aerial predator, and (3) the changes in their locomotor activity at the stage of high primary parasitemia.We show that some behavioural features which might affect a bird's survival during a predator attack (time of reaction, speed of flush flight and take off angle) did not change significantly during primary infection. However, the locomotor activity of infected birds was almost halved compared to control (non-infected) birds during the peak of parasitemia. We report (1) the markedly reduced mobility and (2) the 20% mortality rate caused by P. relictum and conclude that these factors are responsible for the underrepresentation of birds in mist nets and traps during the stage of high primary parasitemia in wildlife. This study indicates that the widespread parasite, P. relictum (pSGS1) influences the behaviour of birds during primary parasitemia. Experimental studies combined with field observations are needed to better understand the mechanisms of pathogenicity of avian malaria parasites and their influence on bird populations.

Generalist haemosporidian parasites are better adapted to a subset of host species in a multiple host community

“…Occasionally, the parasite may end up in tissues of the non‐host species and cause mortality (Ilgūnas et al., ). This will, however, be difficult to detect in nature because studies of wild‐caught birds usually miss those suffering from acute infections (i.e., early stage in infection with high intensity), leading to an underestimate of the potential host range of parasites (Bensch et al., ; Mukhin et al., ). In order to understand the infections in these sporadic host species, experimental infections are required (Palinauskas et al., ).…”

Links between blood parasites, blood chemistry, and the survival of nestling American crows

“…The avian hemosporidian parasites in the genera Leucocytozoon, Plasmodium, and Hemoproteus have been used as a model system in the study of such host-parasite interactions (Atkinson & Van Riper, 1991;Hamilton & Zuk, 1982;Poulin, Marshall, & Spencer, 2000;Zuk & Borrello, 2013), yet their documented costs-and, potentially, the magnitude of selection pressure that they exert-appear to vary widely among hosts, populations, and contexts. They can have devastating impacts in naïve populations (Atkinson & Samuel, 2010), and many studies have reported negative associations with infection in endemic areas, including reductions in condition (Marzal, Bensch, Reviriego, Balbontin, & de Lope, 2008;Merino, Moreno, Sanz, & Arriero, 2000), antipredator behavior (Garcia-Longoria, Moller, Balbontin, de Lope, & Marzal, 2015;Mukhin et al, 2016), mating display behavior (Bosholn, Fecchio, Silveira, Braga, & Anciaes, 2016), survival (Asghar et al, 2015;Krams et al, 2013;Sol, Jovani, & Torres, 2003), and reproductive output (Asghar, Hasselquist, & Bensch, 2011;Knowles, Palinauskas, & Sheldon, 2010;Marzal et al, 2013;Merino et al, 2000). Other studies, however, have reported no associations-or even positive associations-with infection (Cornelius, Davis, & Altizer, 2014;Fargallo & Merino, 2004;Piersma & van der Velde, 2012;Podmokla et al, 2014;Zylberberg et al, 2015), or have reported effects that vary among host species (Atkinson & Van Riper, 1991;Ellis, Kunkel, & Ricklefs, 2014;Sorci, 2013), host population (Piersma & van der Velde, 2012), parasite species (Asghar et al, 2011;Lachish, Knowles, Alves, Wood, & Sheldon, 2011;Marzal et al, 2008), and characteristics of individual hosts…”

Occurrence of endoparasites in Ramphastidae (Aves: Piciformes) in São Paulo Zoo

“…Some of them are considered as a genetic reservoir for many threatened species (WAZA, 2005). Captive environment also offers some specials conditions to animals when compared to wildlife, such as enough food available through the year and for all individuals, protection against predators and veterinary care (Mukhin et al, 2016). On the other hand, when in captivity, animals may live in a highly populated space, which can favour the transmission of infectious diseases and parasites.…”